[]

----- Empty set -----

[(N0, [])]
N0
--- Singleton set ---

[(N9, []),
 (N8, []),
 (N7, []),
 (N6, []),
 (N5, []),
 (N4, []),
 (N3, []),
 (N2, []),
 (N1, []),
 (N0, [])]
N9 > N8 > N7 > N6 > N5 > N4 > N3 > N2 > N1 > N0
--- Most common case ---

[(N9, []),
 (N8, []),
 (N7, []),
 (N6, []),
 (N5, []),
 (N4, []),
 (N3, [N1,N5]),
 (N2, [N5]),
 (N1, [N2]),
 (N0, [])]
N9 > N8 > N7 > N6 > N4 > N3 > N1 > N2 > N5 > N0
--- 0, 1, and 2 successors ---

[(N9, []),
 (N8, []),
 (N7, []),
 (N6, []),
 (N4, [N8]),
 (N3, [N1,N5]),
 (N1, [N2]),
 (N2, [N5]),
 (N5, []),
 (N0, [])]
N9 > N7 > N6 > N4 > N8 > N3 > N1 > N2 > N5 > N0
--- added requirement ---------


Caught an exception in next()
[(N9, [N3]),
 (N7, []),
 (N6, []),
 (N4, [N8]),
 (N8, []),
 (N3, [N1,N5]),
 (N1, [N2]),
 (N2, [N5]),
 (N5, []),
 (N0, [])]
N9 > N7 > N6 > N4 > N8 > N3 > N1 > N2 > N5 > N0
---- no effect of addition ----

[(N9, [N3]),
 (N7, []),
 (N6, []),
 (N4, [N8]),
 (N8, []),
 (N3, [N1,N5]),
 (N1, [N2]),
 (N2, [N5]),
 (N5, [N9]),
 (N0, [])]

---- non-partial ordering ------

Caught an exception, nothing more to show
Exception in thread "main" java.lang.Exception: Giving up

        at POtest.show(POtest.java:21)
        at POtest.main(POtest.java:97)